Update: The Dodge Ram Hybrid has been on-again, off-again for several years. As of mid-March 2010, it’s off—apparently down and out for the count.

Sometime in 2010, Dodge will probably unveil the full hybrid version of its big, bold Ram Pickup. Right now, all we know for sure is that it’ll be called the Dodge Ram 1500 Hybrid.

In February 2009, Chrysler’s Roger Benvenuti, manager of communications for Jeep and Dodge Truck, said only, “I can confirm that we will be introducing the Ram 1500 Hybrid in 2010, but we’re not discussing any of the details at this time.”

Unfortunately, that schedule puts Chrysler a good two years behind General Motors, whose Chevrolet Silverado Hybrid and GMC Sierra Hybrid pickups began arriving at dealers in February and March 2009.

Timing Is Everything

In January 2008, Chrysler announced it would add a hybrid model to its pickup line. According to that announcement, the upcoming Ram Hybrid will feature the company’s 5.7-liter Hemi V8, with a Multi-Displacement System that shuts off the fuel supply to four of its eight cylinders when only partial power is needed. Redesigned for 2009, the standard Ram pickup is offered with a wide array of engines, cabs, lengths, and strengths. It’s actually Chrysler’s highest-volume vehicle, selling 246,000 trucks in 2008—just handful more than the company’s iconic minivans.

Developing a combined 375 horsepower between the engine and the electric motors, the same hybrid system gave the Dodge Durango Hybrid and Chrysler Aspen Hybrid SUVs—which weighed 5,500 pounds—a towing capacity of 6,000 pounds with EPA mileage ratings of 19/20 miles per gallon (city/highway).

Unfortunately, the company’s continuing sales slump and the global economic crisis combined to kill off Chrysler’s hybrid SUVS right at the time they were first shipped to dealers, with fewer than 1,000 built in total.

It’s the Economy, Stupid

With global vehicle markets down 30 to 40 percent and Chrysler begging for low-interest loan guarantees from the US government, the company was forced to submit a reorganization plan to President Barack Obama’s task force on the auto industry in February 2009.

That plan has been viewed with some skepticism by industry analysts, among them Craig Cather, president and CEO of CSM Worldwide. He told a February meeting of the International Motoring Press Association that he felt the company’s plan made overly optimistic assumptions, and that he believed the company would cease to exist in its current form within a year. So the fate of the Dodge Ram Hybrid depends on macro-economic circumstances outside the company’s control.

Demand for full-size SUVs has all but collapsed, so high-volume full-size pickup trucks are the next frontier for large hybrid vehicles. Between Ford, Chevrolet/GMC, and Dodge, body-on-frame pickups sell 1.5 million units a year, and they’ll soon be subject to steeply higher mileage requirements.

A Hard-Working Hybrid

Unless and until most full-size pickups come with a hybrid system as standard—don’t hold your breath—GM and Chrysler may find it challenging to make the payback obvious enough that it will attract buyers among fleets and commercial owners. They buy the bulk of pickups, to use them as working trucks, and they ruthlessly run the numbers on fleet costs. Much less likely to spend anything on making a green statement, they’ll put out the money if they get it back in gasoline saved.

A year ago, we summarized the defunct Durango Hybrid this way: “This is a powerful, capable, and practical vehicle, especially for work utility—and the gas mileage doesn’t totally suck.” The same will apply to the Ram Hybrid …if Chrysler makes it to 2011, that is.